import os
import shutil
import subprocess
import sys

import pytest

# Ensure the project root is on sys.path when running tests.
ROOT = os.path.dirname(os.path.dirname(__file__))
if ROOT not in sys.path:
    sys.path.insert(0, ROOT)


@pytest.fixture(scope="session", autouse=True)
def require_ffmpeg():
    """The tests exercise real encodes; there is little point faking them."""
    for tool in ("ffmpeg", "ffprobe"):
        if shutil.which(tool) is None:
            pytest.skip(f"{tool} is not on PATH", allow_module_level=True)


@pytest.fixture
def make_flac():
    """Return a factory writing a short tagged FLAC file."""

    def factory(path, title="Test Title", artist="Test Artist", album="Test Album", seconds=1):
        path.parent.mkdir(parents=True, exist_ok=True)
        subprocess.run(
            [
                "ffmpeg",
                "-nostdin",
                "-hide_banner",
                "-loglevel",
                "error",
                "-y",
                "-f",
                "lavfi",
                "-i",
                f"sine=frequency=440:duration={seconds}",
                "-metadata",
                f"title={title}",
                "-metadata",
                f"artist={artist}",
                "-metadata",
                f"album={album}",
                "-metadata",
                "track=3",
                str(path),
            ],
            check=True,
            capture_output=True,
        )
        return path

    return factory


@pytest.fixture
def probe_tag():
    """Return a helper reading a single metadata tag from a file."""

    def reader(path, tag):
        completed = subprocess.run(
            [
                "ffprobe",
                "-v",
                "error",
                "-show_entries",
                f"format_tags={tag}",
                "-of",
                "default=noprint_wrappers=1:nokey=1",
                str(path),
            ],
            check=True,
            capture_output=True,
            text=True,
        )
        return completed.stdout.strip()

    return reader